1、October 2016 English price group 14No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 25.220.50!%n“2577527www.din.deDI
2、N EN ISO 28721-5Vitreous and porcelain enamels Glasslined apparatus for process plants Part 5: Presentation and characterisation of defects (ISO 287215:2016);English version EN ISO 287215:2016,English translation of DIN EN ISO 28721-5:2016-10Emails und Emaillierungen Emaillierte Apparate fr verfahre
3、nstechnische Anlagen Teil 5: Darstellung und Charakterisierung von Fehlern (ISO 287215:2016);Englische Fassung EN ISO 287215:2016,Englische bersetzung von DIN EN ISO 28721-5:2016-10Emaux vitrifis Appareils maills pour les installations industrielles Partie 5: Prsentation et caractrisation des dfauts
4、 (ISO 287215:2016);Version anglaise EN ISO 287215:2016,Traduction anglaise de DIN EN ISO 28721-5:2016-10SupersedesDIN 511761:200308www.beuth.deDocument comprises 26 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.10.16 DIN EN I
5、SO 28721-5:2016-10 2 A comma is used as the decimal marker. National foreword This document (EN ISO 28721-5:2016) has been prepared by Technical Committee ISO/TC 107 “Metallic and other inorganic coatings” in collaboration with Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” (
6、Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was DIN-Normenausschuss Materialprfung (DIN Standards Committee Materials Testing), Working Committee NA 062-01-63 AA Prfung von Emails und Emaillierungen. The DIN Standard corresponding to the International S
7、tandard referred to in this document is as follows: ISO 28721-1 DIN EN ISO 28721-1 Amendments This standard differs from DIN 51176-1:2003-08 as follows: a) the standard has been adopted as an EN ISO Standard; b) normative references have been updated. Previous editions DIN 51176-1: 2003-08 DIN EN IS
8、O 28721-5:2016-10 3 National Annex NA (informative) Bibliography DIN EN ISO 28721-1, Vitreous and porcelain enamels Glass-lined apparatus for process plants Part 1: Quality requirements for apparatus, components, appliances and accessories DIN EN ISO 28721-5:2016-10 4 This page is intentionally blan
9、k EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 28721-5 March 2016 ICS 25.220.50 English Version Vitreous and porcelain enamels - Glass-lined apparatus for process plants - Part 5: Presentation and characterisation of defects (ISO 28721-5:2016) Emaux vitrifis - Appareils maills pour les i
10、nstallations industrielles - Partie 5: Prsentation et caractrisation des dfauts (ISO 28721-5:2016) Emails und Emaillierungen - Emaillierte Apparate fr verfahrenstechnische Anlagen - Teil 5: Darstellung und Charakterisierung von Fehlern (ISO 28721-5:2016) This European Standard was approved by CEN on
11、 23 January 2016. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards ma
12、y be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified
13、to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland
14、, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Managemen
15、t Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 28721-5:2016 EForeword .41 Scope .52 Normative references 53 Terms and definitions .54 Enamelling defects .64.1 Colour lines 64.1.
16、1 General64.1.2 Strain lines .64.1.3 Tearings .74.1.4 Pearl lines .84.1.5 Shore lines .84.1.6 Drying cracks 94.2 Boiling defect .104.2.1 Further designations .104.2.2 Description .104.2.3 Origin and causes .114.2.4 Classification 114.2.5 Suggestions for defect treatment 114.3 Rough enamel surface 11
17、4.3.1 Underfired areas .114.3.2 Eggshell .124.4 Dimple .134.4.1 Further designations .134.4.2 Description .144.4.3 Origin and causes .144.4.4 Classification 144.4.5 Suggestions for defect treatment 144.5 Pinholes 144.5.1 Further designations .144.5.2 Description .144.5.3 Origin and causes .154.5.4 C
18、lassification 154.5.5 Suggestions for defect treatment 154.6 Contamination 154.6.1 Chamotte/refractory clay 154.6.2 Scale .164.6.3 Ceramic fibres174.7 Colour deviations .184.7.1 Water marks .184.7.2 Colour stains .195 Repaired areas .205.1 Polished area205.1.1 Further designations .205.1.2 Descripti
19、on .205.1.3 Origin and causes .215.1.4 Classification 215.1.5 Suggestions for defect treatment 215.2 Enamel-covered area after grinding 215.2.1 Further designations .215.2.2 Description .215.2.3 Origin and causes .225.2.4 Classification 225.2.5 Suggestions for defect treatment 22Contents PageEN ISO
20、28721-5:2016 (E) DIN EN ISO 28721-5:2016-10 2European foreword 3European foreword This document (EN ISO 28721-5:2016) has been prepared by Technical Committee ISO/TC 107 Metallic and other inorganic coatings in collaboration with Technical Committee CEN/TC 262 “Metallic and other inorganic coatings”
21、 the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016. Att
22、ention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN-CENELEC Internal Regulations, the national standards organizations o
23、f the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Net
24、herlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 28721-5:2016 has been approved by CEN as EN ISO 28721-5:2016 without any modification. “ EN ISO 28721-5:2016 (E) DIN EN ISO 28721-5:2016-10 3
25、 ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a t
26、echnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters
27、 of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This docume
28、nt was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all suc
29、h patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and doe
30、s not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informa
31、tionThe committee responsible for this document is ISO/TC 107, Metallic and other inorganic coatings, and in collaboration with Technical Committee CEN/TC 262, Metallic and other inorganic coatings.ISO 28721 was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC
32、262, Metallic and other inorganic coatings, in collaboration with ISO Technical Committee ISO/TC 107, Metallic and other inorganic coatings, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).ISO 28721 consists of the following parts, under the general t
33、itle Vitreous and porcelain enamels Glass-lined apparatus for process plants: Part 1: Quality requirements for apparatus, components, appliances and accessories Part 2: Designation and specification of resistance to chemical attack and thermal shock Part 3: Thermal shock resistance Part 4: Quality r
34、equirements for glass-lined flanged steel pipes and flanged steel fittings Part 5: Presentation and characterization of defectsEN ISO 28721-5:2016 (E) DIN EN ISO 28721-5:2016-10 4 1 ScopeThis part of ISO 28721 establishes a system for the cataloguing of defects in enamellings for chemical service an
35、d vessels. In addition, it describes some types of areas in which defects have been treated and which can easily be confounded with enamelling defects. It serves for a consistent language use concerning the designation and characterization of enamelling defects.This part of ISO 28721 is limited to d
36、etectable defects and does not purport to fully take into consideration all occurring types of defects. It does not evaluate enamelling defects; the classification carried out is based on experience and corresponds, as far as possible, to ISO 28721-1.NOTE Regarding the acceptance of glass lined equi
37、pment for use in process engineering, ISO 28721-1 applies.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the lates
38、t edition of the referenced document (including any amendments) applies.ISO 28721-1, Vitreous and porcelain enamels Glass-lined apparatus for process plants Part 1: Quality requirements for apparatus, components, appliances and accessories3 Terms and definitionsFor the purposes of this document, the
39、 following terms and definitions apply.3.1enamelling defectdefect arising during the enamelling of equipment and pipelines to be used in process engineering3.2reparable enamelling defectenamelling defect that can be remedied without thermal post-treatmentEXAMPLE Defect that can be remedied by polish
40、ing.3.3non-reparable enamelling defectdefect in the enamel coating that renders a component unfit for its respective intended use3.4refiringfurther enamel firing (also local), with or without another application3.5re-enamellingcomplete new creation of the enamel coatingEN ISO 28721-5:2016 (E) DIN EN
41、 ISO 28721-5:2016-10 5 4 Enamelling defects4.1 Colour lines4.1.1 GeneralThe enamelling defects strain lines (4.1.2), tearings (4.1.3) and pearl lines (4.1.4) are closely related to one another. The causes of their development and their appearances are similar.4.1.2 Strain lines4.1.2.1 Further design
42、ationsMerged strain lines, linearly upward fused ground coat and hairlines.4.1.2.2 DescriptionStrain lines are lines that are always dark and running parallel, or concentrically in the usually blue or white glass cover coat (see Figure 1). In a severe case of strain lines, a number of bubbles or bli
43、sters in a single line can appear, forming a pearl line (4.1.4).a) White cover coat with macroscopically detectable strain linesb) Lateral view, white cover coat exploring leapt up dark ground coatFigure 1 Strain lines4.1.2.3 Origin and causesStrain lines arise during enamelling due to thermally or
44、mechanically induced stress in the component. When heating up, the ground coat and the covering bisque cracks open. During firing, parts of the ground coat penetrate into the cover coat.Possible causes are the following: a wrong combination of steel/ground coat/cover coat; weld seam made from non-su
45、itable filler material; mixing zones in the weld metal; non-adapted temperature control during enamelling of constructively unfavourable components, e.g. components showing mass accumulation;EN ISO 28721-5:2016 (E) DIN EN ISO 28721-5:2016-10 6 plastic deformation of the component during enamelling.4
46、.1.2.4 ClassificationNon-reparable enamelling defect.4.1.2.5 Suggestions for defect treatmentRe-enamelling, taking into consideration the causes mentioned in 4.1.2.3.4.1.3 Tearings4.1.3.1 Further designationsHairlines.4.1.3.2 DescriptionTearings are mostly dark lines, running parallel or concentrica
47、lly in the cover coat, i.e. lines that are always dark in blue enamel and either dark or light and transparent in white enamel. In contradiction to pearl lines (see 4.1.4), the lines do not show large blisters and are closely related to strain lines (see 4.1.2). Unlike strain lines, however, these l
48、ines are recessed (see Figure 2).Figure 2 Tearings4.1.3.3 Origin and causesTearings arise during enamelling due to thermally or mechanically induced stress in the component. When heating up, the enamel bisque and/or the enamel coating crack(s) open. These cracks merge again during firing. If only the cover coat is affected, dark lines appear. If the crack runs through to the metal surface, blisters in the form of pearl lines
